In many households dependent on the collection of rainwater as a source of drinking water, the collection area is normally the house roof and the rainwater is stored in a tank that can be constructed of iron, polyethylene, or concrete and which is located on a level below and in close proximity to the house roof so that the water flows by gravity down the spouting and to the storage tank.
Wind blown seeds, leaves, sticks, pollen, sand, road dust, bird droppings and dead insects etc can accumulate on the roof.
A problem associated with rainwater stored in a tank is a build-up of sediment and plant material, which has been carried off the roof along the spouting by the rainwater, and into the storage tank. As a result of the decaying plant material, nutrients are released into the surrounding water. It is these nutrients that support colonies of bacteria and protozoa.
The sediment decaying, places an oxygen demand on the tank water. The process of decay can significantly lower the available oxygen in the water.
There are devices to minimise the plant material which is carried off the roof. Devices such as screens that fit into the gutters to prevent the accumulation of leaves and filters or leaf diverters on the spouting outlet and/or the entrance to the tank, also minimise the deposit of leaves in the tank. These devices do not however prevent smaller particles such as seeds, pollen, road dust, sand and broken parts of leaves and sticks etc from accumulating in the rainwater tank.
It is known to vacuum out tanks to remove the build up of sediment, in the same manner that swimming pools can be vacuumed out. The equipment to do so is expensive and it is normal for a householder to engage an independent contractor to occasionally clean out the tank.
The cost of cleaning out a rainwater tank can be several hundred dollars.
As storage tanks are located below the roof, it is necessary to use a pump to either pump the water to a header tank to thus provide pressure to the household water system, or to use the pump itself to provide pressure to the household water system.
The pumps, draw in and break down, the water sodden plant material to minute but still visible particles that contaminate the household water supply.
Sometimes these particles can be clearly seen when a glass of water is poured and are more obvious when water is run into a bath.
In addition the impurities flow into the hot water cylinder where they cause a build up of material within the cylinder itself.
The inventor has come up with a novel and inexpensive system for removing the build up of sediment from rainwater tanks.